Products having a stick-like form for dispensing are generally in the nature of semi-solid or highly viscous materials, such as known cosmetic products which include lipstick, eye shadow, eye liner, mascara and the like. Other products which are dispensable in stick-like form are known as personal care and hygiene products, for example, deodorants, lip balms, sunscreens, insect repellents and the like. Generally, there are known other products such as household products which can be dispensed in stick-like form, for example, adhesives, polishes and the like. There is therefore known a number of products in stick-like form which are dispensable for various applications.
One form of a known dispenser for cosmetics is referred to as a lipstick case. The lipstick case generally includes a housing which is covered by a removable cap when the contained lipstick in stick-like form is in a retracted position. Upon removing the cap, the lipstick is advanced through the housing by means of a mechanism so as to expose the lipstick for application. The lipstick is typically mounted in a holder or a cup, which is engaged by the mechanism to enable the lipstick to be moved within the housing between a retracted storage position and an extended user or application position. In order for the dispenser to function properly, it is a requirement that the lipstick retained within its holder or cup during ordinary handling and use.
To this end, there is known various designs for securing a lipstick to its holder or cup. For example, Vaupel, U.S. Pat. No. 5,560,727 (the disclosure of which is incorporated by reference in its entirety) discloses a lipstick carrier having a spring element provided with an outwardly facing cam which engage a recess at the end of an outer lipstick tube to prevent the lipstick cup from slipping out of the lipstick tube. At other times when the lipstick is retracted, rear engagement lugs on the spring element embed into the lipstick upon engagement of the cam with the inner surface of the lipstick tube to prevent the lipstick from slipping out of the lipstick carrier. However, the securing action is eliminated when the lipstick is fully extending, which can cause the lipstick to accidentally dislodge from the lipstick carrier during use.
Hopgood, U.S. Pat. No. 2,797,803 and Wild, U.S. Pat. No. 1,835,580 (the disclosure of which are incorporated by reference in their entirety) discloses a rigid metal carrier of open cylindrical cup shape. A pair of inwardly directed lugs formed from a portion of the metallic carrier is operative for retaining the inserted stick cosmetic, for example, stick colognes, stick deodorants and the like.
Reichenbach, U.S. Pat. No. 2,302,473 (the disclosure of which is incorporated by reference in its entirety) discloses a lipstick carrier having a metallic cup-shaped carrier formed with an annular inwardly projecting rib to aid in retaining the lipstick within the carrier.
Mazzola, et al., U.S. Pat. No. 5,609,430; Ackermann, et al., U.S. Pat. No. 5,599,124; Lombardi, et al., U.S. Pat. No. 5,197,814; Clark, U.S. Pat. No. 3,083,822; Grau, U.S. Pat. No. 3,838,169; Hultgren, U.S. Pat. No. 3,298,509; Spatz, U.S. Pat. No. 4,820,070 and German Patent No. DE 3442094 (the disclosure of which are incorporated by reference in their entirety) disclose a lipstick carrier provided with a plurality of inwardly directed longitudinally extending ribs for engaging the lipstick and securing same within the carrier.
Croce, U.S. Pat. No. 2,798,599 (the disclosure of which is incorporated by reference in its entirety) discloses a lipstick carrier having a pair of spaced apart helical ribs projecting inwardly for engaging the lipstick. When a lipstick is inserted into the carrier, the lipstick is cammed by the internal ribs so as to turn itself during the insertion operation thereby anchoring the lipstick in the carrier.
Gelardin, U.S. Pat. No. 2,318,152 (the disclosure of which is incorporated by reference in its entirety) discloses a lipstick carrier provided with a pair of inwardly directed tongues formed as dihedral angles with a sharp outer edge. The outer edges of the tongues are notched for anchoring a lipstick within the carrier against displacement therefrom.
Broder, U.S. Pat. No. 2,469,631 (the disclosure of which is incorporated by reference in its entirety) discloses a lipstick carrier having a base plate from which there extends a plurality of triangular-shaped prongs into which the lipstick is pressed.
Safianoff, U.S. Pat. No. 2,815,123 (the disclosure of which is incorporated by reference in its entirety) discloses a lipstick carrier which includes an internal ring supported by a plurality of radially extending ribs into which the bottom of a lipstick is embedded.
Patel et al, U.S. Pat. No. 6,116,801 (the disclosure of which is incorporated by reference in its entirety) discloses a lipstick holder including a plurality of barbs extending from the holder or cup, formed of resilient polymer material having spring-like properties while being resiliently flexible. The barbs, due to their spring-like properties, reorient themselves away from the interior surface of the holder or cup to embed themselves into the lipstick bullet after insertion. Vibration that might tend to cause the product to move axially within the holder or cup, causes the barbs to penetrate further into the product further securing the product from movement. A person of ordinary skill in the art of injection molding of thermoplastic parts, such as the lipstick holder of Patel et al, would recognize the complexity and difficulty of molding the resilient barbs extending well into the interior of the cup.
Notwithstanding the foregoing, there has been recognized a continuous problem of the lipstick or other product to be dispensed in stick-like form being dislodged from its holder or carrier. This can occur when the dispenser is subject to vibration, shock or repeated movement, such as during shipment, dropping of the lipstick case and jostling within the purse or baggage by the user. Under these conditions, it is possible for the base of the lipstick bullet to become dislodged from the cup, and for the formed tip of the lipstick to compress into the inner surface of the cup so as to be deformed. This results in a product which is not acceptable to the consumer, thereby often prompting return of the dispenser by either the distributor or consumer.
A common lipstick holder or cup includes a plurality of spaced apart ribs disposed on the inner surface of the sidewall of the cup which, during the insertion process, exert a resistance pressure by cutting through the outer surface material of the lipstick bullet. Generally, the radially-inward profile of the ribs should be minimized to not produce a distortion in shape or damage in the structural integrity of the molded lipstick bullet. The lipstick package designer is confronted with achieving the goal of maximum retention by using wide and long ribs that extend into the bullet profile, without displacing an excessive volume of the bullet material which can weaken the mechanical strength of the lipstick bullet itself, and can produce internal cracks that can destroy the structural integrity of the bullet.
These aforementioned challenges are even more amplified when the lipstick is a softer lipstick formula.
Accordingly, there is still the room for improvements in dispensers for various products which are provided in stick-like form in the nature of a semi-solid or highly viscous material for a multitude of applications.